Thomas was born in 1699 and his baptism took place on May 14th, 1699 in North Nibley, Gloucester. Thomas' father was Thomas Curnock and his mother was Mary Norris. His paternal grandparents were Thomas Curnock and Elizabeth. He had two brothers and a sister, and also a sibling of unknown gender, named John, John, Joanne and Hestor. He was the second youngest of the five children.